Most woodwork in and around your home will have been painted or varnished. If it is relatively new and in good condition, then it will generally provide a sound surface for new paint. In most cases, however, so many coats of paint have been added on top of each other that woodwork looks sticky, has visible drips or brush marks, has blistered or flaked, or it is impossible to tell exactly how sound the underlying wooden structure is. In these cases, it is far better to strip off the old finish and start afresh.
Removing paint by hand with just a scraper is very hard work and should really be restricted to small areas. There is a variety of scrapers: some have serrated edges for scoring through the paintwork and a flat blade for scraping off; others are triangular in shape – called shave hooks – and can be used on flat and moulded areas. Cabinet scrapers have a rolled steel blade and these remove paint and polish on wooden surfaces but are hard on the hands as constant pressure is needed. Faster methods of stripping include both chemical and mechanical methods. Each has its advantages and drawbacks.
Blow torches burn off paint and varnish and, although they are now available in handy refillable liquid gas containers, they carry a risk of fire. The blow torch technique is to heat the paint or varnish just enough to make it soft so it can be scraped away. Never put a lighted blow torch down and leave it unattended; don’t burn the paint or varnish; and don’t let the hot scrapings fall onto combustible materials, such as the newspaper you put down to protect the floor. Scrapings should be deposited immediately into a metal bucket. You must also take extra care when using a blow torch next to glass or plastic laminates.
While stripping with a flame is fast and efficient, the potential to scorch wood is always there. Paint will easily cover scorch marks, but the appearance of wood that is to be varnished will be spoiled by them. Electric hot-air strippers are ideal for stripping oil-based paints and varnishes from wood and metal. They work almost as quickly as blow torches with less risk of scorching or fire, but the same precautions apply.
Electric sanders are good for preparing painted and varnished surfaces that are to be repainted. Multi-functional and detail sanders are particularly useful as they combine different-shaped bases and profiles that allow you to sand right into corners or around detailed mouldings such as balusters. While it is efficient, electric sanding also removes the top surface of the wood as well as the finish and produces a great deal of dust. Wear a face mask and make sure the room in which you are working is well ventilated.
Liquid Paint Strippers
White spirit is suitable for removing wax and oil finishes on wood but will not remove paint or varnish. Though gentle and effective, it removes the nourishing waxes and oils, thus drying the wood, and can leave it looking dull. Methylated spirit can only be used to remove shellac-based finishes such as French polish and is used by professional furniture restorers because of its ‘gentleness’.
When it comes to stripping large or ‘fiddly’ areas of woodwork, the most convenient methods – although not the cheapest – are gel, liquid, or paste strippers. Because of their fluidity, liquid strippers are only suitable for use on wood that is, or can be laid, horizontal, otherwise it just slips off. Gels are thicker and will ‘grip’ most vertical household joinery. Many proprietary strippers will remove all types of paint, varnish and lacquer but you’ll need to reapply if there are several layers or finish to be removed.
Neutralize the stripper by washing down the wood with white spirit or water; follow the manufacturer’s guidelines. While water is cheaper, it will raise the grain on wood and may cause joints to swell. Despite their claims to ‘low odour’ you must still work in a well- ventilated room and avoid naked flames. Watch out too if you wear spectacles with plastic lenses, and remove watches since the caustic strippers will ‘melt’ plastic.
Paste Paint Strippers
Paste strippers have a thick, creamy consistency, which makes them ideal for stripping vertical and even overhead surfaces, and they can be pressed well into mouldings and intricate shapes. Again they need to be neutralized. They have a tendency to leave the stripped wood somewhat dark. Paste strippers are also available in ‘blanket’ forms: these are expensive but don’t need neutralizing and remove the paint cleanly, requiring very little scraping. This makes them ideal for delicate objects or easily scratched surfaces. Once applied you wait – sometimes for hours – for the paint to solidify onto the blanket, which is then peeled away.
Whatever method you use, work safely and follow manufacturer’s instructions. After wood is stripped, it should be treated as if it is ‘new’ timber: filled and sanded, knots sealed, then primed, and finished.